1. Field of the Invention
The invention relates to an electronic keyboard instrument with a synthesizer, which imitates as realistically as possible the sound of a string instrument, in particular a grand piano, preferably as a silent practice instrument exclusively with a headphone socket.
2. Description of the Prior Art
Professional musicians, in particular pianists, must practice daily on their instruments, which particularly in flats with poorly soundproofed walls is even perceived as a disadvantage by neighbors who are music enthusiasts. Therefore, there has been a trend to provide for the pianist "electronic grand pianos" with a headphone socket, in order that he can do his practice with this otherwise silent instrument without annoying the neighbors. In purely "electronic grand pianos", which have neither strings nor a soundboard to generate the sound, the usual mechanism in conventional pianos is missing and is instead replaced with electric switches, or the like. This means that the pianist, upon pressing down a key perceives a completely different touch than in a conventional grand piano, which has an adverse effect on his practicing.
From U.S. Pat. No. 4,217,803, an electronic keyboard instrument is known in which on the upper face of a lifting member is a weight, which generates an inertia force when the keys are actuated, so that a touch corresponding to a piano key mechanism is supposed to be created. However, the lifting member lies on the tip of an impact tongue, which projects from the upper surface of the key end. Thereby, the inertia force of the weight is felt immediately from the beginning to the end of pressure on the key without any perceivable intermediate gradation.
From U.S. 4,667,553, likewise a lifting member with an additional weight rests on the upper face of a piano key. In addition, below the key front end, a resiliently deformable cup element is provided. If the key is pressed at first only two-thirds of the possible way down, only the weight on the lifting member and another weight on the key end have an effect. With further pressure until full depression of the key, the cup element has to be deformed by the under-side of the depressed keys, so that for the player, an additional pressure sensation is created which is supposed to approximate the natural touch of a piano action. However, this does not do justice to the typical effect of the damping mechanism of a piano or grand piano on the customary key touch. Against this, above all, is the resilience of the cup element.
The object of the invention is, in an electronic keyboard instrument for imitating the sound of a piano or grand piano, so to form the key mechanism that the usual touch of a grand or piano is not lost, but the behavior of the key when touched corresponds as closely as possible to the acoustic original.